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Preemergent Herbicide
Preemergent herbicides are a form of chemical weed control which prevent germinated weed seedlings from becoming established. In some areas of the world, they are used to prevent crabgrass from appearing in lawns. Preemergent herbicides are applied to lawns in the spring and fall, to prevent the germination of weed seeds. They will not affect any established plant. In the spring, they should be applied when air temperatures reach 65–70 °F for four consecutive days. In the fall, they should be applied when nighttime lows reach 55–60 °F for four consecutive nights. "Weed and feed" products which contain both preemergent herbicide and fertilizer in a single product should not be used on southern lawns or warm-season grasses. If applied when preemergent herbicide is needed, the fertilizer may burn or stress the lawn. If applied after the lawn "green-up", weed seeds will have already germinated and the herbicide will be ineffective. Preemergants do not prevent se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pendulum (herbicide)
A pendulum is a weight suspended from a pivot so that it can swing freely. When a pendulum is displaced sideways from its resting, equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward the equilibrium position. When released, the restoring force acting on the pendulum's mass causes it to oscillate about the equilibrium position, swinging back and forth. The time for one complete cycle, a left swing and a right swing, is called the period. The period depends on the length of the pendulum and also to a slight degree on the amplitude, the width of the pendulum's swing. From the first scientific investigations of the pendulum around 1602 by Galileo Galilei, the regular motion of pendulums was used for timekeeping and was the world's most accurate timekeeping technology until the 1930s. The pendulum clock invented by Christiaan Huygens in 1656 became the world's standard timekeeper, used in homes and offices for 270 years, and ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forsythia
''Forsythia'' , is a genus of flowering plants in the olive family Oleaceae. There are about 11 species, mostly native to eastern Asia, but one native to southeastern Europe. ''Forsythia'' – also one of the plant's common names – is named after William Forsyth.Flora of China''Forsythia''/ref>Flora Europaea''Forsythia''/ref>St Andrews Botanic Garden Description ''Forsythia'' are deciduous shrubs typically growing to a height of and, rarely, up to with rough grey-brown bark. The leaves are borne oppositely and are usually simple, though sometimes trifoliate with a basal pair of small leaflets; they range between in length and, rarely, up to , with a margin that is serrated or entire (smooth). Twigs may be hollow or chambered, depending on the species. The flowers are produced in the early spring before the leaves, bright yellow with a deeply four-lobed flower, the petals joined only at the base. These become pendent in rainy weather thus shielding the reproductive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oryzalin
Oryzalin is an herbicide of the dinitroaniline class. It acts through the disruption (depolymerization) of microtubules, thus blocking anisotropic growth of plant cells. It can also be used to induce polyploidy in plants as an alternative to colchicine Colchicine is a medication used to treat gout and Behçet's disease. In gout, it is less preferred to NSAIDs or steroids. Other uses for colchicine include the management of pericarditis and familial Mediterranean fever. Colchicine is taken b .... References External links * Antiparasitic agents Nitrobenzenes Sulfonamides Preemergent herbicides Anilines Microtubule inhibitors {{Pharmacology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pestanal
Sigma-Aldrich (formally MilliporeSigma) is an American chemical, life science, and biotechnology company that is owned by the German chemical conglomerate Merck Group. Sigma-Aldrich was created in 1975 by the merger of Sigma Chemical Company and Aldrich Chemical Company. It grew through various acquisitions until it had over 9,600 employees and was listed on the Fortune 1000. The company is headquartered in St. Louis and has operations in approximately 40 countries. In 2015, the German chemical conglomerate Merck Group acquired Sigma-Aldrich for $17 billion. The company is currently a part of Merck's life science business and in combination with Merck's earlier acquired Millipore Corporation, Millipore, operates as MilliporeSigma. History Sigma Chemical Company of St. Louis and Aldrich Chemical Company of Milwaukee were both American specialty chemical companies when they merged in August 1975. The company grew throughout the 1980s and 1990s, with significant expansion in fac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
